Question

In desert plants, the epidermis has a thick waterproof coating of
A. Cutin
B. Suberin
C. Elastin
D.Chondrin

Answer 1

Hint: Xerophytes acquire several adaptations as they are subjected to high temperatures and scarcity of water. The waxy coating ensures minimal water loss by transpiration and serves as a protective covering.

Complete answer:
-The main adaptation of desert plants is to minimize water loss.
In desert plants, this waxy coating is cutin.
-It also protects the plant against mechanical injury and invasion by parasitic fungi.
-Cutin is a waxy water-repellent substance in the cuticle of plants, consisting of highly polymerized esters of fatty acids. They help desert plants retain moisture for long periods of time.
-Thick cuticle, sunken stomata, fewer stomata, less exposed surface, increased water storage, long vertical root, etc ensures their survival in dry conditions.

Additional Information:
-Xerophytes have spines to protect plants from animals that search for water.
-Wide holes present on leaves help these plants to remove excess water.
-Long Loop of Henle and small glomeruli are the two major adaptations that animals acquire in desert conditions.
-Suberin provides protection and can help to prevent water loss.
-Elastin is an important protein involved in maintaining the elasticity of tissues.
-Chondrin forms a matrix in which cells are embedded in cartilage.
So the correct answer is “Cutin”.

Note: Most of the desert plants appear to be swollen. Do you know why? It is due to their ability to store water in their stem and it can be consumed later. They have holding sacks for the same. Leaves are reduced into spines to reduce transpiration loss. Cutin is embedded in a complex mixture of relatively nonpolar waxy compounds.